Eels & Elvers

Eels & Elvers

Eels and elvers present particular challenges for fish deterrence and guidance systems.

Eels have poor hearing ability, so sound-based systems are rarely effective in controlling their movement. Instead, FGS has developed light-based solutions that ensure these species are guided away from intakes.

Eels spawn at sea before entering coastal and transitional waters and maturing in rivers. They then return to the sea to spawn and concerted migrations put them at risk of being drawn into water intakes and harmed or destroyed.

Protecting eels and elvers from harm

Much of our work with eel populations has come in response to regulatory requirements to aid the migration of adult silver eels to the sea. Behavioural barriers at water offtakes help maintain stocks, while elver and eel passes help ensure efficient movement.

Light-based deflection systems such as HIL provide effective deflection, with outputs tailored for individual species. FGS has successfully completed projects to guide eels in various environments, some examples of which can be found below.